Oh Bitey was reading holding my breath about poor puppy!! Thank god it's nothing serious. I've had dogs for a long time now (although his is only my second puppy, always been rescues) and what I've learnt is that 99% of the time little ailments turn out to be nothing at all. Even initially worrying things like pup having a heart murmur when we got him has turned out to be nothing. I'm a lot more laid back about issues now - even little lumps and bumps are generally a 'keep an eye on it' thing. Limps are always worth checking though - our older dog ruptured his cruciate ligament and it was a NIGHTMARE. Crate rest for 6 months with an active border collie!! so I don't blame you for being worried at all.
AmIAWeed sounds like you're getting there with the night time routine!! Totally agree it's all about offering an alternative straight away and I did say 'no' if he but us, giving him something else to chew and then walking off if he continued. Not what everyone would do but it worked for us and he doesnt bite or mouth us at all now. It does pass! Just be consistent and don't allow him to do it even in play.